Multi-stage motor



April 20, 1965 J. w. SUTHERLAND MULTI-STAGE MOTOR 2 Shets-Sheet 1 Filed Sept. 18, 1963 INVENTOR 1 475m) illsz/fi/aeuy/vo United States Patent 3,179,207 MULTI-STAGE MQTOR John William Sutherland, Nashville, Tenn, assignor of fifty percent to Arthur Casciaro, Nashville, Tenn. Filed Sept. 18, 1963, Ser. No. 309,636 Claims. (Cl. 185-3) This invention relates to a multi-stage motor, and more particularly to a multi-stage, tension-wound motor.

One object of this invention is to provide a multi-stage, tension-wound motor, such as a rubber-band motor, for propelling a toy vehicle, such as an airplane. 7

Another object of this invention is to provide in a toy vehicle, twin-rubber-band motor stages adapted to automatically operate in succession for propelling the vehicle approximately twice as long as a single stage rubber-band motor.

A further object of this invention is to provide a dualstage motor for driving a rotary shaft, in which each motor stage is a tension-wound motor, such as a rubberband motor or a coil-spring motor adapted to store mechanical rotational energy by winding and to discharge the energy by unwinding.

Another object of this invention is to provide a novel means for transmitting in stages the rotational mechanical energy from a plurality of tension-wound motor stages to a driven shaft.

' A further object of this invention is to provide in a dual-stage, tension-wound motor, novel means for automatically maintaining the stored rotational energy in the second stage while the first stage is driving a rotary shaft, and for automatically operatively engaging the second stage with the driven shaft when the energy in the first state is expended.

Further objects and advantages of the invention will be apparent from the following description taken in conjunction with drawings, wherein:

FIG. 1 is a side elevation of the invention as applied to driving the propeller of a toy airplane, fragmentarily shown, in a first operative position;

FIG. 2 is a top plan view of the invention as disclosed in FIG. 1;

FIG. 3 is a section taken along the line 3-3 of FIG. 1;

FIG. 4 is a section taken along the line 4-4 of FIG. 1;

FIG. 5 is a viewsimilar to FIG. 2, disclosing the motor in its second operative position, with the propeller removed;

FIG. 6 is a front end view of the invention disclosed in FIG. 5;

FIG. 7 is a view similar to FIG. 2 showing the motor in its third operative position; and

FIG. 8 is a front end view of the device as disclosed in FIG; 7.

Referring now to the drawings in more detail, the invention will be described in its particular application to the driving of a propeller it of a toy airplane. The propeller 10 is rigidly mounted to the front end of a driven shaft 11, journaled at its rear end for rotational movement in a bearing 12 on the frame 13 of the airplane. The forward portion of the driven shaft 11 is also rotatably journaled in a mounting plate 14 rigidly secured to the frame 13 by means of the top brace 15 and the bottom brace 16.

Fixed to the driven shaft 11 between the rear bearing 12 and the mounting plate id is clutch member, such as a frusto-conical friction driven gear 18 tapering inwardly toward the front of the airplane. In order to increase the frictional surface of the driven gear 13, a skirt 19 of soft rubber or other frictional material may be fitted in a recessed portion of the driven gear 18. The gear 18 might also be provided with circumferential grooves to accommodate spaced annular rubber bands, not shown.

ddldid? First and second drive shafts 21 and 22 are also rotatably mounted in the mounting plate 14, parallel to, equally spaced from, and in substantially the same plane as the driven shaft 11. The shafts 21 and 22 are also mounted to freely reciprocate axially through mating openings in the mounting plate 14. The front end of each drive shaftZl and 22 is provided with a cam head 23 and 24, respectively, which limits the rearward movement of each drive shaft 21 and 22. Fixed on the first drive shaft 21' is a clutch member, such as a frusto-conical friction first drive gear 27 tapering inwardly toward the rear of the air plane for normal frictional engagement with the driven gear 18. Also fixed to the second drive shaft 22 is a similar clutch member, such as frusto-conical friction drive gear 28 normally engaging the other side of the driven gear 18. As disclosed in FIGS. 2, 5 and 7, the drive gears 27 and 28 may be fluted with elongated friction grooves 29 in order to improve their frictional engagement with the driven gear 18. t

A first motor means 31 is provided for driving the first drive shaft 21 and a second motor means 32 is provided for driving the second drive shaft 22, which may be in selective driving engagement with the driven shaft 11 through the respective gears 27, 28 and 18 in order to rotate the propeller 19.

Each motor means 31 and 32 will be referred to as a tension-wound motor or motor stage, which will not only include the typical rubber-band motor employed in toy airplanes, but also coil-spring motors, or any other type of mechanical motor including a member which is adapted to store rotational energy when the member is rotated or wound, and adapted to expend rotational energy when counter-rotated or unwound. The specific motor means 31 and 32 disclosed in the drawings comprise the rubber bands 33 and 34 fixed at their rear ends, not shown, to a stationary part-of the frame 13, and connected at their front ends to hooks 35 and 36, respectively, fixed in the rear ends of the drive shafts 21 and 22.

In order to selectively engage and disengage the drive gears 27 and 28 with the driven gear 18, a cam plate li is provided for selectively thrusting the cam heads 23 and 2d forward from the mounting plate 14. The cam plate 40 is in the form of a disc and is pivotally mounted about the driven shaft 11 for rotational sliding engagement with the front face of the mounting plate 14. The cam plate 40 is retained against the mounting plate 14 by means of a cap ll. Formed in the cam platedti are a pair of arcuate slots 43 and 44 forming segments of circles, whose radii are equal to the spacing between the axis of each drive shaft 21 and 22 and the axis of the driven shaft 11. The first drive shaft 21 is adapted to extend through the slot 43, while the second drive shaft 42 is adapted to extend through the arcuate slot 44. The first arcuate slot 43 is provided with an enlarged sloping recess 45 extending about two-thirds the length of the slot 43 to provide a cam seat for the cam head 23L The remainder of the cam slot 43 comprises a cam groove 16 for supporting the cam head 23 in a forward axial position, as disclosed in FIG. 7, engaging a cam surface formed by the front face of the cam plate 4d. The arcuate slot 44, as best disclosed in FIG. 6, includes a large tapered recess at each end of the slot 44 to provide cam seats 47 and 48 while tr e portion of the slot 44 between the cam seats 47 and 48 comprises a cam groove 4h for thrusting forward the cam head 2-4 for engagement on the cam surfaces formed by the front face of the cam plate 4% adjacent to the groove 49.

A handle extends radially from the cam plate 40 so that the cam plate it? may be manually rotated about the driven shaft 11. As best disclosed in FIG. 3, a lug 51, which may be spring biased forward, is seated in the mounting plate 14 in order to lock the handle 5d and the Patented Apr. as, less 3 cam plate 40 in its first operative position as disclosed in FIGS. 1-4.

In order to automatically rotate the cam plate 40 when the handle 50 is not locked behind the lug 51, and the cam plate 40 is not frictionally held against the mounting plate 14, an elongated elastic member, such as the rubber band 55, is held in tension at one end by hook 56 mounted on the periphery of the mounting plate 14 and its other end by the hook 57 mounted on the periphery of the cam plate 40. Thus, the cam plate 4%) is constantly biased to rotate in the direction of the arrows disclosed in FIGS. 6 and 8 by the tension member 55.

In order to lock the second drive gear 28 against rotational movement when it is disengaged from the driven gear 18, any means may be provided on the rear of the mounting plate 14 which will lock the gear 28 against rotational movement in its forward position, as disclosed in FIG. 5, but which will permit it to be axially returned to engage the driven gear 18 by means of the wound tension member or rubber band 34, when unlocked. The particular locking means disclosed in the drawing is a half thread 59 mounted on the rear of the mounting plate 14 and a mating half thread 60 mounted on the front face of the gear 28. Other types of locking means might include various types of cams or locking lugs, not shown.

The operation of the invention will now be described in conjunction with a toy airplane having a propeller and employing spring tension-wound motor means 31 and 32 of the rubber-band type.

With the cam plate 40 in its first operative position, disclosed in FIGS. l-4, the handle 50 is locked in its first position by the ing 51, while the elastic member 55 is in tension to bias the cam plate 40 toward rotational movement in a counter clock-wise direction, as viewed in FIG. 3. In this first operative position, the cam heads 23 and 24 are both seated in their respective cam seats 45 and 47, the drive shafts 21 and 22 are slightly biased axially rearwardly by means of rubber bands 33 and 34 in their respective motor means 31 and 32. In the first operative position, both drive gears 27 and 28 frictionally engage the driven gear 18. By manually rotating the propeller10 the rotational motion of the driven shaft 11 is transmitted from its driven gear 18 through both drive gears 27 and 28 to their respective drive shafts 21 and 22 to simultaneously wind both of the rubber bands 33 and 34, respectively, to store the desired amount of rotational energy in both motor stages 31 and 32, as shown in FIG. 5.

If the propeller 10 is released after the rubber bands 33 and 34 have been wound, and while the cam plate 49 is in its first operative position disclosed in FIGS. 1-4, both motor means 31 and 32 will discharge their rotational energy simultaneously through the unwinding rubber bands 33and 34 to drive the gear 18, shaft 11 and propeller 10 with more power than a single motor means 31 or 32. However, both motor means 31 and 32 discharging simultaneously will expend themselves in the same or less amount of time than a single unwinding motor.

However, to carry out the purpose of this invention, the propeller 10 is held stationary after the desired amount of energy is stored in both of the motor means 31 and 32. Then the handle 50 is released from the looking ing 51 and rotated from its first operative position disclosed in FIG. 3 to its second operative position disclosed in FIG. 6. This operation thrusts the cam head 24 forward to ride over the cam surfaces formed by the cam groove 49, to disengage the drive gear 28 from the driven gear 18 and thrust the drive shaft 22 forward until the half threads 59 and 60 engage to lock the gear 28 against counter-rotational movement and to store the energy in the twisted band 34 of the motor means 32. When the cam plate 40 is shifted from the first to the second operative position, the cam head 23 remains in the cam seat 45 to maintain the drive gear 27 in frictional engagement with the driven gear 13.

With the cam plate 40 now in the second position, the operator of the airplane may release the propeller 10 and the airplane, which will immediately be driven by the first stage motor means 31 as the rubber band 33 unwinds to drive the shaft 21, first drive gear 27, driven gear 18, driven shaft 11 and the propeller It When the rubber band 33 is nearly completely unwound so that practically all of the energy in the motor means 31 has been expended, its axial tension on the drive shaft 21 to bias. it toward the rear is substantially reduced, thus reducing the frictional engagement between the cam head 23, the cam plate 40 and the mounting plate 14.

As this frictional engagement diminishes, the tension in the elastic band 55 is strong enough to overcome the frictional engagement between the cam plate 40 and the mounting plate 14 to automatically rotate the cam plate 41) from the second operative position disclosed in FIG. 6 to the third operative position disclosed in FIG. 8 to thrust the cam head 23 forward out of its cam seat 45 and upon the cam surfaces formed by the groove 46. At the same time, the rotating cam plate 4% permits the cam head 24 to be carried rearwardly into the cam seat 48 by means of the axial tension produced by the twisted rubber band 34. As the cam head 24 recedes, the half thread 60 disengages the half thread 59, and the drive gear 28 engages the driven gear 18 in order to transmit rotational energy of the second stage motor means 32 to the driven shaft 11 and the propeller 11). Of course, when the cam head 23 is thrust forward, it automatically disengages the drive gear 27 from the driven gear 18. Thus, the second stage motor means 32 takes over the propulsion of the airplane after the first stage motor means 31 has expended its energy.

It is obvious that this invention may be applied to other types of toy vehicles, such as toy motor boats, as well as for many other applications where successive multiplestage, tension-wound motor means can be successfully employed for rotating a driven shaft. As previously mentioned, it will be understood that other types of motor means may be employed, such as coil springs or watch spring mechanisms which store rotational energy upon winding and discharge energy upon unwinding.

It is also within the scope of this invention to provide more than two motor stages for successively rotating a driven shaft. Such a multiple stage motor could be developed by mounting a plurality of drive shafts and gears circumferentially around the driven gear 18 and forming the cam slots in a cam plate to maintain all of the drive gears, except one, disengaged from the driven gear.

It will be apparent to those skilled in the art that various changes may be made in the invention without depart ing from the spirit and scope thereof, and therefore the invention is not limited by that which is shown in the drawings and described in the specification, but only as indicated in the appended claims.

What is claimed is:

1. A multi-stage motor comprising:

(a) a driven shaft,

(b) a driven clutch member fixed on said driven shaf (c) a first drive shaft,

(d) a first drive clutch member mounted on said first drive shaft, (e) a second drive shaft, (f) a second drive clutch member mounted on said second drive shaft,

(g) mounting means for rotatably supporting said driven shaft, and for rotatably supporting said drive shafts for independent axial movement parallel to said driven shaft,

(11) first tension-wound motor means for storing and expending rotational energy, operatively connected to said first drive shaft,

(1') second tension-wound motor means for storing and expending rotational energy, operatively connected to said second drive shaft,

(j) cam means on said mounting means operative in a first position to maintain said first clutch member in driving engagement with said driven clutch member but to axially thrust said second drive shaft to disengage said second clutch member from said driven clutch member, and operative in a second position to maintain said second clutch member in driving engagement with said driven clutch member, but to thrust said first drive shaft to disengage said first clutch member from said driven clutch member, and

(k) means for automatically shifting said cam means from said first position to said second position when the energy in said first motor means is expended.

2. The invention according to claim 1 in which said cam means comprises a first cam head on said first drive shaft, a second cam head on said second drive shaft and a cam plate movably mounted on said mounting means for engaging said cam heads, said cam plate being movable to said first operative position for camming only said second cam head to axially thrust said second drive shaft away from said second motor means, and movable to said second operative position for camming only said first cam head to axially thrust said first drive shaft away from said first motor means.

3. The invention according to claim 1 further providing means on said mounting means for automatically locking said second drive shaft against rotational movevent in said first operative position.

4. The invention according to claim 2 in which said cam plate includes first cam seat means for receiving said cam heads in a normal position when said drive clutch members engage said driven clutch member, second cam seat means for receiving said first cam head and first cam surface means for engaging said second cam head in said cam plate in said first operative position, second cam surface means for engaging said first cam head and third cam seat means for engaging said second cam head in said cam plate in said second operative position, and means for shifting said cam plate between said normal position, said first position and said second position.

5. The invention according to claim 4 in which said cam plate is rotatably mounted about the axis of said driven shaft, and the cam seat and surface means for each of said cam heads comprises an arcuate slot in said cam plate for receiving said corresponding drive shafts and cam heads for each rotational position of said cam plate, and elastic means for circumferentially connecting said cam plate to said mounting means for automatically biasing said cam plate from said first to said second position.

References Cited by the Examiner UNITED STATES PATENTS 1,682,267 8/28 Daniel. 1,820,967 9/31 Enyeart. 1,936,072 11/33 Roderick. 2,028,845 1/36 Reid. 2,200,686 5/40 Beckman. 2,459,871 1/49 Cole 9 2,470,675 5/ 49 Allan et a1. 185-37 2,477,421 7/49 Roderick 185-37 FOREIGN PATENTS 385,012 12/32 Great Britain.

EDGAR W. GEOGHEGAN, Primary Examiner. 

1. A MULTI-STAGE MOTOR COMPRISING: (A) A DRIVEN SHAFT, (B) A DRIVEN CLUTCH MEMBER FIXED ON SAID DRIVEN SHAFT, (C) A FIRST DRIVE SHAFT, (D) A FIRST DEVICE CLUTCH MEMBER MOUNTED ON SAID FIRST DRIVEN SHAFT, (E) A SECOND DRIVE SHAFT, (F) A SECOND DRIVE CLUTCH MEMBER MOUNTED ON SAID SECOND DRIVE SHAFT, (G) MOUNTING MEANS FOR ROTATABLY SUPPORTING SAID DRIVEN SHAFT, AND FOR ROTATABLY SUPPORTING SAID DRIVE SHAFTS FOR INDEPENDENT AXIAL MOVEMENT PARALLEL TO SAID DRIVEN SHAFT, (H) FIRST TENSION-WOUND MOTOR MEANS FOR STORING AND EXPENDING ROTATIONAL ENERGY, OPERATIVELY CONNECTED TO SAID FIRST DRIVE SHAFT, (I) SECOND TENSION-WOUND MOTOR MEANS FOR STORING AND EXPENDING ROTATIONAL ENERGY, OPERATIVELY CONNECTED TO SAID SECOND DRIVE SHAFT, (J) CAM MEANS ON SAID MOUNTING MEANS OPERATIVE IN A FIRST POSITION TO MAINTAIN SAID FIRST CLUTCH MEMBER IN DRIVING ENGAGEMENT WITH SAID DRIVEN CLUTCH MEMBER BUT TO AXIALLY THRUST SAID SECOND DRIVE SHAFT TO DISENGAGE SAID SECOND CLUTCH MEMBER FROM SAID DRIVEN CLUTCH MEMBER, AND OPERATIVE IN A SECOND POSITION TO MAINTAIN SAID SECOND CLUTCH MEMBER IN DRIVING ENGAGEMENT WITH SAID DRIVEN CLUTCH MEMBER, BUT TO THRUST SAID FIRST DRIVE SHAFT TO DISENGAGE SAID FIRST CLUTCH MEMBER FROM SAID DRIVEN CLUTCH MEMBER, AND (K) MEANS FOR AUTOMATICALLY SHIFTING SAID CAM MEANS FROM SAID FIRST POSITION TO SAID SECOND POSITION WHEN THE ENERGY IN SAID FIRST MOTOR MEANS IN EXPENDED. 